Evaluating the Dynamics of Vegetation Cover Along the Great Green Wall in Yobe State, Nigeria Using NDVI Analysis

The Great Green Wall (GGW) is an important project in northern Nigeria that helps restore degraded lands and reduce desertification and the risks associated with shifting Sahara deserts and sand dunes while promoting land restoration and conservation using both commercial and forest tree species. However, there is a serious risk that these objectives won't be met due to insecurity, conflicts, and poor weather conditions. Even though Governmental and Non-Governmental Organizations (NGOs) have funded the project and included it in the state's development plans for GGW initiatives, the scientific method for analyzing vegetation cover dynamics since its inception has not received the necessary attention. In this regard, this study decided to monitor the changes in the vegetation cover of the Great Green Wall within Yobe State, Nigeria, from 2015 to 2023. The vegetation dynamics were monitored using Landsat 8 Operational Land Imager (OLI) for 8 years at 2-year intervals. The result shows that there was an increase in vegetation cover from 35,000 hectares in 2017 to 78000 hectares in 2021. However, there was a total decrease of 23,498 hectares in the spatial distribution of vegetation cover from 2021 to 2023. This decrease can be attributed to climate change and anthropogenic activities that will be included in the design and implementation of policies of the GGW to achieve its objectives.